Hi. I'm using a std::map to store font glyphs so that I can look them up by character. (Can't simply use an array since I use unicode characters.)

Anyway, when I try to do the following:


GCC gives me this long and incomprehensible STL error message:

Quote:/Path/to/File.cpp:164: error: no match for ternary 'operator?:' in '((const Qoph::Font*)this)->Qoph::Font::m_glyphs. std::map<_Key, _Tp, _Compare, _Alloc>::end [with _Key = wchar_t, _Tp = Qoph::Font::GlyphMetrics, _Compare = std::less<wchar_t>, _Alloc = std::allocator<std::pair<const wchar_t, Qoph::Font::GlyphMetrics> >]().std::_Rb_tree_const_iterator<_Tp>::operator== [with _Tp = std::pair<const wchar_t, Qoph::Font::GlyphMetrics>](((const std::_Rb_tree_const_iterator<std::pair<const wchar_t, Qoph::Font::GlyphMetrics> >&)((const std::_Rb_tree_const_iterator<std::pair<const wchar_t, Qoph::Font::GlyphMetrics> >*)(& itr)))) ? ((const Qoph::Font*)this)->Qoph::Font::m_unkownGlyph : itr. std::_Rb_tree_const_iterator<_Tp>::operator* [with _Tp = std::pair<const wchar_t, Qoph::Font::GlyphMetrics>]()'

It seems to me that the compiler is looking for a overloaded ternary operator (weird, because I didn't think the ternary operator was overloadable in C++), or that the result of "(m_glyphs.end() == itr)" isn't a bool, which it surely should be.

All the Glyph structures and typedefs follow.


If anyone can see the problem here, please let me know.

Is GlyphMapConstItr your own class/subclass, or is it just a typedeffed Map<types>::iterator? If the former, then you may have to make sure that you overload operator ==, and make sure that it takes Map<types>::iterator. If the latter, then I don't know, since it should already have operator == overloaded correctly. (I'm pretty sure the operator == is somehow the root of your problem, though)

GlyphMapConstItr is defined as:

Tey putting parenthesis like this:
foo=(a?b:c);

It's a const iterator, therefore you can't modify what it points to. I think this should work:

Thanks OneSadCookie. Tha was one of the problems. The other was that
... : *itr;
should have been
... : (*itr).second;
since a std::map iterator points to a std :: pair.

Sometimes I feel really stupid. although, in my defense, the error message wasn't the world's most helpful.

Thank you all for the help.

Just for the record, using the form itr->second instead of (*itr).second seems cleaner.

I'm not sure iterators are guaranteed to provide ->, where they are guaranteed to provide *... but I can't remember why I might think this

OneSadCookie Wrote:I'm not sure iterators are guaranteed to provide ->, where they are guaranteed to provide *... but I can't remember why I might think this

I have no idea why you think that, iirc both * and -> are valid for dereferencing an iterator, and I don't recall reading -> was optional: http://www.sgi.com/tech/stl/trivial.html